Countersunk hole in m etal articles



(No Model.) 2 Sheets-Sheet 1 S. L. ALLEN.

GOUNTBRSU-NK HOLE IN METAL ARTICLES. No. 350,908. Patented Oct. 19, 1886.

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(No Model.) I 2 Sheets-Sheet 2.-

i S. L. ALLEN.

COUNTERSUNK HOLE IN METAL ARTICLES. No. 350,908. Patented Oct. 19, 1886.

C v/ Q/W ml INVENTOK 5yu4v Attorney I or upper side of the hole to have a countersink.

UNITED STATES PATENT Orricnt SAMUEL L. ALLEN, .OF GINNAMINSON, NEW JERSEY.

COUNTERSUNK HOLE IN METAL ARTICLES.

SPECIFICATION forming part of Letters Patent No. 350,908, dated October 19, 1886.

' Application filed May 27, 1886. Serial No. 203,478. (No model.)

To all whom, it may concern:

Be it known that I, SAMUEL L. ALLEN, of Oinnaminson, Burlington county, and State of New Jersey, have invented certain new and useful Improvements in the Construction of Holes in Metal Objects of Various Kinds, of which the following is a true and complete specification, reference being had to the annexed drawings, forming a part of this specification.

My invention relates to holes which are more especially used for attaching the metal object of which they form a part to something else-as, for instance, a cultivator-tooth to its standard.

That the attached piece of metal may present a finished appearance and have a smooth surface when in its position, I cause the outer The countersink as usually hitherto made has diminished the supporting metal about it, and has weakened the metal where it should be the strongest, as the point of attachment is the point of the greatest strain. To obviate this weakness, and to produce special strength, I cause a sleeve to be formed on the inner or under side of the hole, as hereinafter described.

The object of my invention is to produce an attachment hole or' holes in a piece of metal provided with a strengthening-sleeve, as hereinafter described.

To illustrate my invention I have selected and shown in the drawings a metallic plow mold-board and cultivator-tooth. This I usually make of sheet metal struck up into the required shape. The mold-board or cultiva tor-tooth is attached to the standard of the implement to which it belongs by means of a bolt passed through an attaching-hole in the blade of the board or tooth and the standard to which it is attached. It is desirable that the head of the bolt be countersunk into the face of the blade, so that it may present a smooth surface to the soil as it passes through it. I use a bolt having ashank of any suitable shape, preferably square, for attaching the mold-board or tooth to its standard. The countersink is made in shape to correspond with the head of the bolt, and the sleeve is made to correspond with the shank of the bolt. When the shank of the bolt is inserted into the sleeve, the two become substantially integral, and the blade or tooth cannot turn on the bolt. The sleeve is fitted to a suitable depression in the standard of the machine to which the board or tooth is attached. The board or tooth is in this manner attached to the standard firmly and strongly, and neither the tooth or its bolt can move independently of the other. The sleeve serves a threefold purpose: It strengthens the metal around the bolt-hole. Its inside surface acts as a sleeve to engage with the shank of the bolt, while its outside surface affords a connection with the article to which it is attached, as above shown in the case of the tooth and its standard. An important advantage, also, is the impossibility of drawing the bolt-head through the piece of metal in which the hole is formed, even if the bolt-head is ever so small and imperfect. WVith a plain countersink it is almost impossible to keep the bolt-heads from drawing through the piece of metal in which they are when the bolt is subjected to great pressure, even though its head is quite large. With a hole provided with a countersink and sleeve such as I have described I am enabled to use bolts having very small heads.

I have illustrated in the accompanying drawings my invention by means of a cultivator-tooth and plow mold-board.

Figure 1 is a longitudinal section of a cultivator-tooth through the line a a of Fig. 3, showing the countersink and the sleeve. Fig. 2 is a perspective view of the bolt used, showing the square shank and the shape of the head. Fig. 3 is a perspective view of the tooth, showing the sleeve. Fig. 4 is a transverse section of the tooth through the center of the bolt-hole. Fig. 5 is a perspective view of the mold-board, showing the two bolt-holes provided with sleeves. Fig. 6 is a plan view of the under side of the same. Fig. 7 is a section of the same through the line as m.

A is a harrow-tooth, preferably made of struck-up steel. B is the bolt by which it is attached to the standard of the machine, having a head, b, a square shank, b, and nut b 0 is the countersink in the face of the blade to receive the head Z) of the bolt 13.

D is the sleeve of the hole of the board or tooth.

E is a plow mold-board, preferably made of struck-up steel.

A metallic plate or article provided with a countersunk hole, the walls of which extend out into a tubular sleeve formed at right an- I 5 gles to the plate and integral therewith, as set forth. 4

In witness whereof I have hereunto set my hand.

SAM. L. ALLEN.

WVitnesses:

H. E. GARSED, G. DUBREE. 

